McLean, E. M. | Search bioRxiv

bioRxiv2026

Both genetic and social inheritance influence female aggressive and submissive behavior in a wild primate

Agonistic interactions are important determinants of resource access in wild animals, but their genetic basis remains poorly understood. Here we use a quantitative genetics approach to estimate the heritability of aggressive and submissive behavior of wild female baboons, considering relative rates of both individual and dyadic aggression and submission. To control for the social inheritance that creates kin-based dominance hierarchies, we implemented a multi-matrix model that included a social status similarity matrix alongside the additive genetic matrix. Despite a substantial contribution of social inheritance, especially for submissive behavior, we found heritable components for both aggressive and submissive behavior (h2=0.21 and h2=0.09-0.11, respectively). In dyadic models, aggressive behavior was primarily influenced by the aggressor's genotype (a direct genetic effect), while submissive behavior was primarily affected by the social partner's genotype (an indirect genetic effect). Finally, we found evidence for a negative genetic (but not phenotypic) correlation between aggressive and submissive behavior within dyads, and a negative genetic correlation between submissive behavior and eliciting submissive behavior. Together, our results highlight how direct genetic, indirect genetic, and social inheritance effects combine to influence primate social behavior.

evolutionary biology↗

bioRxiv2020

Genetic ancestry predicts male-female affiliation in a natural baboon hybrid zone

Opposite-sex social relationships are important predictors of fitness in many animals, including several group-living mammals. Consequently, understanding sources of variance in the tendency to form opposite-sex relationships is important for understanding social evolution. Genetic contributions are of particular interest due to their importance in long-term evolutionary change, but little is known about genetic effects on male-female relationships in social mammals, especially outside of the mating context. Here, we investigate the effects of genetic ancestry on male-female affiliative behavior in a hybrid zone between the yellow baboon (Papio cynocephalus) and the anubis baboon (P. anubis), in a population in which male-female social bonds are known predictors of lifespan. We place our analysis within the context of other social and demographic predictors of affiliative behavior in baboons. Genetic ancestry was the most consistent predictor of opposite-sex affiliative behavior we observed, with the exception of strong effects of dominance rank. Our results show that increased anubis genetic ancestry is associated with subtly, but significantly higher rates of opposite-sex affiliative behavior, in both males and females. Additionally, pairs of anubis-like males and anubis-like females were the most likely to socially affiliate, resulting in moderate assortativity in grooming and proximity behavior as a function of genetic ancestry. Our findings indicate that opposite-sex affiliative behavior partially diverged during baboon evolution to differentiate yellow and anubis baboons, despite overall similarities in their social structures and mating systems. Further, they suggest that affiliative behavior may simultaneously promote and constrain baboon admixture, through additive and assortative effects of ancestry, respectively. HIGHLIGHTSO_LIOpposite-sex social relationships can have important fitness consequences. C_LIO_LIIn hybrid baboons, genetic ancestry predicted male-female affiliative behavior. C_LIO_LIBoth an individuals genetic ancestry and that of its social partner mattered. C_LIO_LIMale-female affiliation was assortative with respect to genetic ancestry. C_LIO_LIDominance rank and group demography also influenced male-female social affiliation. C_LI

evolutionary biology↗